Bio data change auto-rejection

[Krono]

Hi,

I was wondering why does the system sometimes automatically reject some of the changes. In the past I've had tattoo details auto-rejected, today birth date change was rejected. I thought that the whole point of references section in the edit form was to provide proof that the change makes sense. But it doesn't seem to matter as changes probably won't get to the approval process with this auto-rejection crap.

So, yeah, what are the rules for auto rejection?

TIA!